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1 /* ======================================================================== |
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2 * Bootstrap: affix.js v3.3.5 |
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3 * http://getbootstrap.com/javascript/#affix |
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4 * ======================================================================== |
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5 * Copyright 2011-2015 Twitter, Inc. |
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6 * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE) |
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7 * ======================================================================== */ |
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8 |
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9 |
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10 +function ($) { |
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11 'use strict'; |
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12 |
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13 // AFFIX CLASS DEFINITION |
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14 // ====================== |
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15 |
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16 var Affix = function (element, options) { |
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17 this.options = $.extend({}, Affix.DEFAULTS, options) |
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18 |
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19 this.$target = $(this.options.target) |
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20 .on('scroll.bs.affix.data-api', $.proxy(this.checkPosition, this)) |
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21 .on('click.bs.affix.data-api', $.proxy(this.checkPositionWithEventLoop, this)) |
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22 |
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23 this.$element = $(element) |
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24 this.affixed = null |
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25 this.unpin = null |
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26 this.pinnedOffset = null |
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27 |
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28 this.checkPosition() |
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29 } |
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30 |
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31 Affix.VERSION = '3.3.5' |
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32 |
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33 Affix.RESET = 'affix affix-top affix-bottom' |
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34 |
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35 Affix.DEFAULTS = { |
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36 offset: 0, |
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37 target: window |
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38 } |
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39 |
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40 Affix.prototype.getState = function (scrollHeight, height, offsetTop, offsetBottom) { |
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41 var scrollTop = this.$target.scrollTop() |
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42 var position = this.$element.offset() |
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43 var targetHeight = this.$target.height() |
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44 |
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45 if (offsetTop != null && this.affixed == 'top') return scrollTop < offsetTop ? 'top' : false |
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46 |
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47 if (this.affixed == 'bottom') { |
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48 if (offsetTop != null) return (scrollTop + this.unpin <= position.top) ? false : 'bottom' |
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49 return (scrollTop + targetHeight <= scrollHeight - offsetBottom) ? false : 'bottom' |
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50 } |
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51 |
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52 var initializing = this.affixed == null |
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53 var colliderTop = initializing ? scrollTop : position.top |
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54 var colliderHeight = initializing ? targetHeight : height |
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55 |
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56 if (offsetTop != null && scrollTop <= offsetTop) return 'top' |
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57 if (offsetBottom != null && (colliderTop + colliderHeight >= scrollHeight - offsetBottom)) return 'bottom' |
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58 |
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59 return false |
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60 } |
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61 |
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62 Affix.prototype.getPinnedOffset = function () { |
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63 if (this.pinnedOffset) return this.pinnedOffset |
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64 this.$element.removeClass(Affix.RESET).addClass('affix') |
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65 var scrollTop = this.$target.scrollTop() |
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66 var position = this.$element.offset() |
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67 return (this.pinnedOffset = position.top - scrollTop) |
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68 } |
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69 |
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70 Affix.prototype.checkPositionWithEventLoop = function () { |
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71 setTimeout($.proxy(this.checkPosition, this), 1) |
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72 } |
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73 |
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74 Affix.prototype.checkPosition = function () { |
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75 if (!this.$element.is(':visible')) return |
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76 |
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77 var height = this.$element.height() |
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78 var offset = this.options.offset |
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79 var offsetTop = offset.top |
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80 var offsetBottom = offset.bottom |
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81 var scrollHeight = Math.max($(document).height(), $(document.body).height()) |
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82 |
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83 if (typeof offset != 'object') offsetBottom = offsetTop = offset |
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84 if (typeof offsetTop == 'function') offsetTop = offset.top(this.$element) |
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85 if (typeof offsetBottom == 'function') offsetBottom = offset.bottom(this.$element) |
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86 |
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87 var affix = this.getState(scrollHeight, height, offsetTop, offsetBottom) |
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88 |
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89 if (this.affixed != affix) { |
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90 if (this.unpin != null) this.$element.css('top', '') |
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91 |
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92 var affixType = 'affix' + (affix ? '-' + affix : '') |
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93 var e = $.Event(affixType + '.bs.affix') |
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94 |
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95 this.$element.trigger(e) |
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96 |
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97 if (e.isDefaultPrevented()) return |
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98 |
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99 this.affixed = affix |
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100 this.unpin = affix == 'bottom' ? this.getPinnedOffset() : null |
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101 |
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102 this.$element |
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103 .removeClass(Affix.RESET) |
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104 .addClass(affixType) |
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105 .trigger(affixType.replace('affix', 'affixed') + '.bs.affix') |
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106 } |
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107 |
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108 if (affix == 'bottom') { |
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109 this.$element.offset({ |
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110 top: scrollHeight - height - offsetBottom |
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111 }) |
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112 } |
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113 } |
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114 |
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115 |
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116 // AFFIX PLUGIN DEFINITION |
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117 // ======================= |
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118 |
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119 function Plugin(option) { |
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120 return this.each(function () { |
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121 var $this = $(this) |
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122 var data = $this.data('bs.affix') |
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123 var options = typeof option == 'object' && option |
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124 |
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125 if (!data) $this.data('bs.affix', (data = new Affix(this, options))) |
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126 if (typeof option == 'string') data[option]() |
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127 }) |
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128 } |
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129 |
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130 var old = $.fn.affix |
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131 |
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132 $.fn.affix = Plugin |
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133 $.fn.affix.Constructor = Affix |
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134 |
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135 |
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136 // AFFIX NO CONFLICT |
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137 // ================= |
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138 |
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139 $.fn.affix.noConflict = function () { |
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140 $.fn.affix = old |
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141 return this |
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142 } |
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143 |
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144 |
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145 // AFFIX DATA-API |
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146 // ============== |
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147 |
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148 $(window).on('load', function () { |
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149 $('[data-spy="affix"]').each(function () { |
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150 var $spy = $(this) |
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151 var data = $spy.data() |
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152 |
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153 data.offset = data.offset || {} |
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154 |
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155 if (data.offsetBottom != null) data.offset.bottom = data.offsetBottom |
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156 if (data.offsetTop != null) data.offset.top = data.offsetTop |
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157 |
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158 Plugin.call($spy, data) |
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159 }) |
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160 }) |
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161 |
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162 }(jQuery); |